What's the difference between Class A and Class B of a three-pipe ship?

First of all, the types of competency certificates are different:

According to the provisions of Article 9 of the Rules for Examination, Assessment and Certification of Seagoing Crew in People's Republic of China (PRC), the category, grade, position and scope of application of the certificate of competency:

(a) the certificate of competency is divided into four categories: A, B, C and D. ..

Therefore, the types of certificates held by A-class crew, B-class crew, C-class crew and D-class crew are different.

Second, the applicable positions are different:

1.A certificate of competency is applicable to: the captain, chief officer, second officer and third officer of ships with 3000 gross tonnage and above in the infinite navigation area; Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer.

2. Class B certificates of competency are applicable to: the captain, chief officer, second officer and third officer of ships with a gross tonnage of 3,000 tons or above near the Hainan Sea Area; The captain, chief officer, second officer and third officer of a ship with a gross tonnage of 500 to 3,000 tons in the sea area near Hainan; Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer.

3. Class C certificates of competency are applicable to: the captain, first mate, second mate and third mate of ships with a gross tonnage of 3,000 tons or more sailing along the coast; Captain, first mate, second mate and third mate of ships with a gross tonnage of 500 to 3,000 tons in coastal navigation areas; Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer, Chief Engineer.

4. Class D certificate of competency is applicable to: the captain, first mate, second mate and third mate of ships with gross tonnage of less than 500 tons near the sea navigation area; Chief engineer, chief engineer, chief engineer, chief engineer, chief engineer and chief engineer of ships with main propulsion power unit less than 750 kW in coastal navigation areas; The crew on duty of a ship with a gross tonnage of less than 500 tons in the inshore navigation area; Mechanic on duty for ships with main propulsion power unit less than 750 kW in coastal navigation area.

Third, the training internship conditions are different:

Baoyi, Grade C, seafarers and mechanics must receive six months of professional training in regular training units, including "basic safety" and "skilled sailing" for seafarers. B-class and C-class sailors and mechanic crew members should practice at sea (offshore and coastal) for six months after obtaining the Examination Certificate.